This invention relates to television systems, and more particularly, to the use of memory in interactive television program guide systems.
Cable, satellite, and broadcast television systems provide viewers with a large number of television channels. Viewers have traditionally consulted printed television program schedules to determine the programs being broadcast at a particular time. More recently, interactive electronic television program guides have been developed that allow television program information to be displayed on a viewer's television.
Interactive television program guides, which control user-interface functions, i.e. channel-selection or interactive program inspection, are typically implemented on set-top boxes. Although set-top boxes are often provided to subscribers with only the program guide application installed and a certain number of pre-determined channels, cable system operators often would like to have the capability to add more channels to their cable television channel line-up. Cable system operators may also want to install additional applications in the set-top boxes in their system when such features become available. For example, operators might wish to add application software to the set-top boxes to support a home shopping service, a home banking service, an Internet access service, or some other such service.
However, the amount of memory available in a set-top box is limited. Because the amount of memory required by a conventional program guide is fixed, it may not be possible to install new application software in a set-top box if the program guide application has already been installed. An example of an electronic program guide with a memory size that is fixed is shown in Lazarus U.S. Pat. No. 5,652,613. Although it might be possible to reserve the needed memory capacity for the future installation of new applications by initially using a program guide with a fairly small memory requirement, such a reduced-size program guide would generally not be able to provide the same level of functionality as a full-sized program guide.
It is therefore an object of the present invention to provide a system in which the memory requirements of a program guide may be adjusted when it is desired to install additional applications.
It is a further object of the present invention to provide a system in which the memory requirements of a program guide may be adjusted to accommodate the addition of new channels to the existing channel line-up.